Lenovo has posted an battery check-up utility after a "limited number" of ThinkPad owners began complaining about power packs that wouldn't recharge or provided a suspiciously low capacity.

The Chinese company stressed that the problem was not extensive and that batteries suffering from the capacity issue do not pose a safety risk.

The issue affects ThinkPar R60, R61, T60, T61, X60 and X61 machines sold worldwide. It manifests itself as a sudden drop in the battery charge displayed by Windows or by a very short battery life.

In some cases, Lenovo's Power Manager app will flag up an "irreparable damage" or "battery cannot be charged" error message.

The diagnostic tool can be downloaded from Lenovo's website here. If the tool determines that your battery is eligible, Lenovo said, it will open up the site where a free replacement battery can be requested. ®